Multiple spindle broaching lathe



April 21., 1942. w. F. GROENE ETAL MULTIPLE SPINDLE BROACHING LATHEFiled April 3.0, 1940 12 Sheets-Sheet l INVENTOR. WXLURN F. GROEYW.HRROLD J. S\EKMRNN April 21, 1942. w. F. GROENE ETAL 2,280,229

MULTIPLE SPINDLE BROACHING LATHE Filed April :50, 1940 12 Sheets-Shet 2HGJI l I INVENTOR.

April 21, 1942.

W. F. GROENE ETAL MULTIPLE SPINDLE BROACHING LATHE Filed April 30, 1940l2 Sheets-Sheet .3

April 21, 1942. w, GRQENE ETAL 2,280,229

MULTIPLE SPINDLE BROACHING LATHE Filed April 30, 1940 12 Sheets-Sheet 4FITS- N INVENTOR.

WHJJRN F. GRQENE BY HHROL'D J. SEKNRNN.

April 21 1942. wfF. GROENE ETAL NG LATHE MULTIPLE SPINDLE BROACHI FiledApril so, 1940 12 Sheets-Sheet e INVENTOR. W\LL\RM F. GRQENE April 1942-w. F. GROENE ETAL 2,280,229

MULTIPLE SPINDLE BROACHING LATHE Filed April 50, 1940 12 Sheets-Sheet '7IN VENT OR.

'mLuRm. F. GROENE. HRROLD .s. suaKMnNN BY 9M A ril 21, 1942. w. F.GROENE arm. 2, 8 ,2

MULTIPLE SPIINDLHBROACHING LATHE Filed ApriLSO, 1940 12 sheets-sheet 9INVENTOR.

WLLIRM F. GROENE. HAROLD J. snaxmmm I w. F. GROENE ETAL MULTIPLE SPINDLEBROACHING LATHE April 21, 1942.

12 Sheets-Sheet 10 Filed April 30, 1940 INVENIOR. WlLURM EGROENE BYHHRQLD '5. S\E.'KMRNN April 21, 1942. w. F; GROENE ETAL 2,280,229

MULTIPLE SPINDLE BROACHING LATHE Filed April 30, 1940 12 Sheets-Sheet 11BY M W. F. GROENE ETAL MULTIPLE SPINDLE an'oacnme LATHE Filed April 30,1940 12 Sheets-Sheet l2 INVENTOR. YHLLPM E GRGENE HRRQLD J. SEKMRNHPatented Apr. 21, 1942 MULTIPLE SPINDLE BROACHING LATHE William F.Groene and Harold J. Siekmann, Cincinnati, Ohio, assignors to The R. K.Le Blond Machine Tool Company, Cincinnati, Ohio, a corporation ofDelaware Application April 30, 1940, Serial No. 332,540

2 Claims.

This invention pertains to multiple spindle broaching lathes formachining the bearing portions of multi-throw internal combustion enginecrankshafts. More particularly, this invention pertains to a machine forfinish machining the line bearings and associated portions of suchcrankshafts by means of a series of progressive metal cutting operationsundertaken successively by different types of tool applications to thevarious bearing portions to be machined.

An object of this invention is to provide a series of progressive finishbroaching and shaving steps on the line bearings of a crankshaft wherebysuch bearings may be finished to an extremely high degree of accuracy inwhich the runout, that is the concentricity of the machined bearingsrelative to the true axis of "rotation on the crankshaft, is well withinthe limits of rough grinding operations formerly necessary to accomplishthis result.

It is a purpose of this lathe to machine these bearing portions by ametal cutting operation to an accuracy of .001 of an inch run-out orless by means of a series of broaching and shaving tool applications ina progressive manner. This unique arrangement is far superior to roughgrinding operations heretofore undertaken which consume large amounts ofproductive time and are expensive because of the problem of wheel wearand the impracticability of grinding the small protruding surfacesassociated with the line bearings, particularly when required to do soat high productive speeds on a plurality of bearings at the same timewith great accuracy.

An object of this invention is to set forth a multiple spindle indexingmachine in which a series of progressive broaching and shaving steps maybe undertaken on the bearing portions of multi-throw crankshafts.

An object of this invention is to chuck the crankshaft and rotate it bysuitable chucking means which supports the ends of the crankshaft oncenters and provides a suitable center drive chucking mechanismintermediate these centers for rotating and supporting the crankshaftduring the machining operations. It is then the object to index thecrankshaft, while so held, to

a work station and there to apply broaches which may first do broachingoperations on certain specific parts of the line bearing portions of theshaft; then to index the crankshaft to another work station where asecond series of broaches may do broaching operations on, other portionsof these line bearings; and then finally to m dex the crankshaft to afinal work station where a series of shaving tools perform the finalaccurate sizing operations on the diameter portions of the crankshaftbearings.

It is also an object to provide, in such a multiple spindle indexbroaching lathe for machining the line bearings of a crankshaft,different types of broaching tools and shaving tools at the various workstations all operating simultaneously at one or more or all of thevarious work stations to complete the final high accuracy of the linebearing portions of the crankshaft.

Another object of this invention is to provide a broaching lathe forsimultaneously accurately finish machining line bearing portions of thecrankshaft, which have been previously roughed out, by the applicationfirst at a work station of a series of broaching tools to breach all ofthe side wall portions of the line bearings of the crankshaft; toprovide at a second work station a series of broaching tools forsimultaneously broaching all of the diameter portions of these linebearings of the crankshaft; and then to provide at a final work stationmeans to accurately size these diameter portions by means of theapplication of a series of shaving tools to the broached diameterportions machined at the second work station.

A further object of this invention is to provide in a multiple spindlebroaching lathe, a rotatable carrier member having a series of workspindles, each comprising a center drive chucking device and tailstockswith centers mounted on the carrier member and to provide at a series ofwork stages, appropriate broaching tools adapted to engage the workpieces held in the work spindles of the rotatable carrier member,

which member may be indexed to bring the work and at which are located aseries of broaching Still another object of this invention is to providein a multiple spindle broaching lathe having a series of work stationsand a carrier member for progressively presenting a work piece to thevarious work stations, a series of broaching means at said work stationswhich operate in planes angularly related to each other for performingbroaching operations on the work pieces indexed to the respective workstations.

Another-rbiect of this invention is. to provide in a multiple spindlebroaching and shaving lathe, a rotatable carrier member forprogressively presenting a series of work pieces to a series of workstations in such a lathe, at which work stations are located a series ofbroaching and shaving cutting devices which progressively performmachining operations on said'work piece as it is indexed to the variouswork stations.

Another object of this invention is to provide in a multiple spindlebroaching lathe, a series VII, and IX, particularly showing th manualcontrol for actuating the clutch shifter rods for spindle stoppin andstarting the work spindle of work stations having a series of broachingcutting devices, and a work carrier member for progressively presentingwork pieces to said work stations and to provide indexing mechanism foractuating the carrier member whereby at the completion of the machiningoperation at any one stage, the tools are held in fed-in position, whilethe work carrier member is partially indexed and then after said workcarrier is partially indexed, the broaching cutters are retracted tofully withdrawn position, whereupon the indexing of said carrier membercontinues to bring the work pieces to the next work station 7 forcontinuation of the cutting cycle.

And still another object of this invention is to provide in conjunctionwith a multiple spindle broaching lathe having a rotatable carriermember and a series of work stations having broach- 1 ing mechanismsthereat, means whereby the various work spindles maybe rotated atdefinite predetermined diiIerent speeds for each work station, so thatbreaching operations may be undertaken at a variety of spindle speedsfor each particular work station to which the work piece machine shownin Figure I as indicated by the line II-II in Figures I and IX.

Figure III is a vertical transverse section through the lathe on theline III-III of Figures I and IX.

Figure IV is a 7 machine as indicated by the line IVIV of Figure 1.

Figure V is a vertical transverse section right hand end elevation ofthe and for operating them at low and high speeds.

Figure IX is a diagrammatic longitudinal section through the workcarrier drum and driving mechanism for operating the center drive workspindles at low speed and high speed and for arresting rotation of saidspindles shown substantially on the line IXIX of Figures II and III.

Figure X is a diagrammatic view substantially on the line X-X of FigureV, XV, and XVI showing machining of the line bearing portions of acrankshaft at work station One where a series offace 'broaching toolsare simultaneously applied'to all ofthe radial extended surfaces of theiin bearing portions which have been previously roughed out in a prioroperation.

Figure XI is a diagrammatic view substantially on the line XI--XIofjFigures V, XVII, and XVIII showing the application of a series ofbroaches simultaneously to all of the diameter portions of the linebearing portions of the crankshaft at station Two.

Figure XII is a diagrammatic view substantially on the line X[IXII ofFigures V, XIII, and XIV, showing th simultaneous application of aseriesof shaving tools for the final sizing of the diameter portions of theline bearings of the crankshaft being machined at station Three.

Figure XIII is a section on the line X[IIXIII of Figure IHI showing theapplication of the shaving tools to the machining of the diameterportions of the line bearings of the crankshaft.

Figure XIV is a plan view on the line XIV- XIV of Figure XIII.

Figure XV is a plan view of the face broaches shown on the line XV-XV ofFigures V and XVI. Figure XVI is a section on the XVI-XVI of Figure Xshowing the side view of the face broaching tools-for machining theradially extended portions of the line bearings of the crankshaft.

Figure XVII is a plan view of the diameter broaches shown on the lineXVIIXVII of Figures V andXVIII.

FigureXVIII is a side elevation in section on the line XVIIIXV.IJI ofFigure XI showing the broaching tools for the diameter portions of thethrough the machine on the line VV of Figures I, X, XI, and xn.

' Figure V1 is an enlarged fragmentary view of a portion of the front ofthe machine shown in Figure I, particularly indicating the arrangementof the control lever for stopping a'nd starting of the workspindles'when at the loading station as indicated by the line VI-VI onFigures II and VIII. v I Figure VII is an enlarged fragmentary view ofthe cam ends for the clutch shifting rods for line bearings of thecrankshaft.

Figure XIX is a diagram showing the electric and hydraulic controlmechanism for the lathe.

General organization As shown in Figure I, the machine comprises a'baseI, upon which is mounted the upright supports 2 and 3 and on top ofthese supports is mounted a housing 4 which ties the upper ends of thesesupports together-and holds them in rigid position on the base of themachine. In appropriate bearings 5 and 6, in the respective supports 2and 3 is journaled the work spindle carrying and indexing drum I onwhich are mounted a series of center drive chuck housings 8, in whichare journaled appropriate center drive ring gears 9 containing centerdrive chuckin mechanism l0 and also the cooperating centering devices ortailstocks ll, having the usual slidably adjustable barrels l2, carryingthe centers 18,

which engage the ends of the crankshaft C to be machined in the lathe,whereby the crankshaft is chucked and rotated intermediate its ends andsupported on its ends by these centers in the tailstocks I I.

Referring particularly to Figure V,/ a fundamental purpose of the drum Iand associated parts is to index the crankshafts to be machined whilecarried in the center drive chucks l and on the centers I! of thetailstocks II to a series of three work stations as designated in thisfigure as work station one, work station two, and work station three. Afourth station, at which no cutting is done is designated as the loadingstation and is provided for inserting and removing the crankshafts C toand from the work spindles while the machining operations are takingplace at the other three work stations. 7,

, Machining operations to be performed After the work piece orcrankshaft C has been loaded in the chucking and centering devices atthe loading station, the drum I rotates in a clockwise direction, asseen in Figure V, carrying the work 0 into properly indexed position forcutting action at work station one. It is to be understood that the workcrankshaft, which is specifically illustrated in Figures X, XI, and XII,hasbeen previously rough machined on the surfaces to be finished by thevarious machining operations to be undertaken in this machine invention;

this previous roughing operation being done on a machine of a charactershown, for example in Patent #1,93'4,976, issued November 14, 1933, orPatent #2,069,107, issued January 26, 1937.

I For an illustrative purpose, the finished broaching and shavingoperation to be successively carried on this machine are shown appliedto .the finish machining of the four line bearings, flange end, and studend of a typical six throw four line bearing multi-throw crankshaft,shown in the Figures X, XI and XII. This crankshaft has the linebearings, i4, i5, i6, and i1, and the stub end l8, and flange end l8,comprising the line bearing portions of the crankshaft to be finishtools, FB, carried onappropriate tool feeding dem) vices 35, 36 31, 38,39, 40, and 4| which are arranged to be actuated so as to feed thebroaches F'B substantially tangentially of the diameter portion D,Figure XVI, of the various line bearings so that their cutting teeth 42travel in a plane 5:,

indicated by the line XV-XV of Figures V and XVI. These face broaches'FBhave cutting edges 42a on their sides which are arranged to engage thevarious radiallyextending face' portions 43 of the line bearings and theflange l9, and the 30 oil groove 44 and chamfer 45 of the stub end ofthe crankshaft to thereby simultaneously complete the finishing toaccurate axial spacing of these surfaces for proper registerwith thecooperatingparts of the internal combustion engine in which'thec-rankshaft is to be placed. The various broaches F3 are fed asindicated in Figures V and XVI, theline bearing portions beingpositioned relative to the broaches at 46 at the beginningof the cuttingoperation and reach the position 41 after the broaches have been fullyfed past the linebearing portions of the crankshaft tocomplete thebroaching of the radially extendingfacevportions 43 of the linebearings.

The crankshaft C is then moved to work staof the drum 1 where themachining comprises that of simultaneouslyfeeding a series of diameterbroaching tools as best shown in Figures V,

5 XI, XVII, and XVIII. These diameter broaching tools DB are carried onappropriate tool feeding devices 48, 49, 50, 5|, 52,and 53 so that theircutting teeth 54 feed tangentially .past the diameter'portion D of thevarious line hearings in a plane indicated by the line XVIIXVII ofFigures V and XVIIL. The relative position of the work crankshaft at thebeginning'of the diameter broaching operation is shown at the position55 of the line bearings in Figure XVIII and at the completion of thediameter broaching operation is in the relative position indicated at 56in this figure. At this work station two the diameter portions arebroached to an initial finished dimension of relatively high accuracy,and

.may be considered as an initial finish broaching operation preparatoryto the final sizing of these portions to very accurate dimensions atwork station three.

Having thus completed these broaching operations the work C is thenindexed to work station Three where the finish machining the linebearings of the crankshaft consists in applying a series of shavingtools S to the finish broached diameter portions of the crankshaft so asto bring their final dimensions to an extremely high degree of accuracyand finish. By tangentially feeding these series of shaving tool S asshown in Figures V and XIII in a tangential plane substantially asindicated vby the line XIV-XIV on these figures. These shaving tools arecarried on appropriate tool feeding-devices 51, 58, 59, 60, GI and 82which effect the proper tangential feeding movement in the variousshaving tools S in the plane XIV'--XIV. In this last work station Threethe final accurate sizing of'the line bearing diameters is accomplishedby the removal of any irregularities in these work surfaces as caused bythe diameter broaches DB at the work station Two so that the resultingfinish and accuracy of these. diameter portions is of extremely highquality.

These shaving tools are of the typical shaving tool constructioncommonly used in machine tool practice having their cutting edgesarranged at an angle to axis of rotation 63 of the work piece andfeeding in the tangential plane XIV-XIV relative to the diameter of thework surface to be cut so that the cutting edge of these shaving toolsprogressively travel relativelyvaxially across'the work surface so as toproduce a highly accurate finished surface on the. various line bea ingportions. The work C is lktated at a predetermine speed at each of thwork stations and independently of the speeds being effected at theother work stations. .Inthis particular disclosure the work spindlesare, rotated at relatively high speed while at work station One and atwork station Two, while the work is rotated at relatively low speed atwork station Three, during the finish shaving operation. Means areprovided for automatically causing these spining tools is beingperformed at station Three at relatively low spindle speed to effect avery high degree of finish on the work diameters machined at this laststation.

All of the tool feeding devices pointed out in Figures X, XI, and XIIand as shown together in Figure V, operate simultaneously by suitablemechanisms to be described so that machining operations aresimultaneously performed at all three of the work stations during thecomplete cutting cycle of the machine.

It is to be clearly understood that this machining procedure is welladapted to machining crankshafts from the rough forgings byappropriately constructing the broaching tools at work station One andwork station Two to accommodate the additional material that must beremoved when rough forglngs are to be machined. For instance, it is wellwithin the scope of our invention to add one or'more work stations andwork spindle to the above outlined procedure, for the preliminaryroughing out of the work piece with suitable broaching apparatus. Also,

we may utilize two or more center drive chucking devices l in housings 8for each work spindle and utilizing a chucking method outlined forexample in Patents 1,843,359, 1,934,976, and 2,030,020, or any othersuitable chucking device which might be used for gripping the crankshaftby means of rough the unmachined webs. We might also incorporate aloading device as illustrated in our Patent 1,700,721' to facilitateloading of the work in the center drive work spindles. We have thusabove set forth the general nature of the machining to be done in thislathe, and we will now proceed with the detailed description of theoperating mechanism and functions performed by this machine to carry outthe machining operations on the work piece above.

Drive for work spindles Noting Figures I and IV, the source of drivingpower for rotating the work spindles is derived from the main driveelectric motor 84, mounted on the bracket 85 attached to the base of themachine by suitable screws 66. This motor has the usual pinion 81adapted to drive the gear 88 carried on the main longitudinal driveshaft 89, appropriately carried in a bearing 10 in the trunnion H at theright hand end of the drum 1. This shaft 69 extends to the left end ofthe drum 1, as that shown in Figure IX, where it is connected bysuitable splined shaft connection 12, with the central shaft 13,journaled in bearings 14 and 15 in the indexing housing I8, whichhousing is appropriately fixed on the flange portion 1A of the drum 1 bysuitable screws 11. On this central shaft 13 are fixed the small pinionl8 and the larger gear 19. The gear 18 simultaneously engages the fourgears 88, rotatably journaled on suitable bearings 8| on each of thework spindle drive shafts 82 while the larger gear 19 simultaneouslyengages the smaller gears 88 also rotatably iournaled on suitablebearings 84 on these drive shafts 82, so that with constant speed ofrotation of the drive shaft 69 by the constant speed motor 64, the gears88 will be rotated at relatively slow speed whereas the gears 88 will berotated at relatively high speed on the various drive shafts 82.Associated with each of the series of gears 80 and 88, are therespective clutch mechanisms indicated at 85 and 88, whereby therespective gears 88 and 88 may be alternately connected or disconnectedwith respect to the various drive shafts 82, so that when clutches 85are engaged the drive shafts are rotated at relatively slow speed fromthe shaft 89 and when the clutches 86 are engaged to connect the gears83 with their drive shafts 82, these drive shafts 82 will be rotated atrelatively high speed.

Suitable actuating mechanism comprising the shifting shoe 81 actuated bythe shifter yoke 88 fixed on the sliding shifter rod 89 carried in thehousing 18 serve to engage one or the other of the clutches and 86 or torender both of said clutches inoperative when moved to an intermediateposition between the clutches.

The ends of these shifting rods 89 are provided with enlarged cam ends89a as best shown in Figures II, VII and IX, in which operate a seriesof fixed cam rollers 90, 9|, 92, and 93, which are carried onappropriate studs 94, fixed in the upright support 2 'of the machineframe. These studs 94 are variously axially projecting from the lefthand face of the support 2, so as to effect an automatic shifting of theshifter bars 89, as the drum 1 and the housing 18 are rotated inindexing motion to carry the work spindles from one work station to thnext. For instance, in the particular construction and arrangementillustrated in this case wherein it is the. object to provide relativelyhigh speed of rotation for the work spindle while at station One andstation Two and relatively low speed at station Three, the rollers 90and 9| are carried on their respective studs projecting only a shortdistance out from the support 2, so that as the cam ends 89C as the drum1 is indexed from loading station up to work station One. When the drumindexes .a work spindle to station Two the rod 89 will remain to theright, Figures VII and IX,

since the roller 9| is positioned the same as the roller 90 to maintainthis high speed driving relationship at work station Two.

However, when the drum indexes to station Three the roller 92 carried onits stud 94 project P far to the left from the support 2, so that itwill engage the surface 89D and will thereby ultimately move the rod 89to the left to the low speed position, the roller eventually riding upon the surface 89E as shown in Figure VII to effect operation of theclutch 85, thereby effecting a low speed drive between the gears 18 andfor relatively slow rotation of the drive shafts 82 for the work spindlewhen at work station Three.

As this spindle again rotates back to the loading station, the roller 93carried on its stud 94, projects to an intermediate position betweenthat of the rollers 90-9| and the roller 92, so as to re-' turn the rodsomewhat to the right to a neutral position at which time neither of theclutches and 86 are operative as is shown in Figure VII. Thus as theworks spindle finally arrives back at the work station, it isautomatically stopped from rotation and also at the same time, as thisspindl rotates into the work station an automatic braking device comesinto play to prevent coasting rotation of the spindle so that theoperator may promptly get at the unchucking of the work from the spindleand the reloading of work in the spindle for the next cycle of op- Thisbraking mechanism is shown best in Figures II and Ix and comprises aspring urged shoe 95 carried on appropriate studs 96 on the bell shapedmember 91, which is journale on the bearing surface 35 of the housingI6. an is prevented from rotating with the indexing of the drum I andthe housing I6 by the link 99 connected to the hydraulic reservoir tankI fixed on thebase I by screws I I3 by a suitable pin IOI andattached'to the lugs I02 of the member 91,

. Indexing mechanism Mechanism for rotating the workspindle carryingdrum I to'the respective indexed positions of the various work stationsand the loading station comprises a fluid pressure driven indexing motorI II best shown in Figures I, II, and XIX, suitably fixed to the oilreservoir "0 having a driving pinion H9 secured to the its power outputshaft.

sothat it does not rotate but floats on the bear- 1:;

ing surface" of the housing I6, thus maintaining the brake shoe 95 inproper oriented position with respect to the indexing position of thedrum' and housing "It. This brake shoe as is adapted to engage thebrakedrums I03, one of which 2 is fixed on each of the driveshafts 82 andwhich drums I03 engage the brake shoe at the precise time that itsrespective work spindle is brought to the loading station. Suitablesprings I04 serve to automatically allow the shoe to ride up 5 on to thebrake drums I03 as theyindex into the loading stations and also toprovide sufficient braking pressure to permit the spindle to heretatedunder manual operation when at the loading stations while at the sametime providing 30 sufhcient friction for quickly arrestingrotation#2,138, 522 dated Novemin Figures VI and VIII, on a suitable rock shaft40 I06 carried in the bracket I01 fixed to the front of the housing 2 ofthe machine. On this rock shaft I06 is mounted a gear I00 which engagesa rack I09 on the slidably mounted stud I I 0 carrying the roller IIIwhich is provided in the same path as followed by the ends 09A of theshifter rods 09 which engage the various rollers 90, 9|, 92 and 93. Themovable stud H0 is so positioned that when the .work spindle is in theloading station, its roller will be positioned around 50 the roller IIIshown in Figure VII so that the lever I05 when swung to the positionI05A, Figure VI, it will effect the high'speed operation of the workspindle and when swung to the position A compound gear, comprising thelarge gear I meshing with the motor pinion H9 and the small gear I2Imeshing with the large indexing gear I22, is suitably supported on astud I23, fixed to the frame 2 of the lathe. This arrangement affords ameans whereby the fluid operated indexing motor III'is adapted torevolve the drum I through the largegear I22 which is fixed to thefiange portion IA of the drum 1 of the lathe.

A fluid pressure actuated indexing plunger mechanism isprovided fordefinitely positioning the drum 1 and work spindles carried thereon inproper position relative to the work stations and work loading position,this mechanism be interlocked with the operation of the fluid indexingmotor III in a manner to be described; This indexing plunger I23A ismounted for sliding movement in a bracket I23 fixed to the left handside of the upright support 2'by suitable screws I24 and is arranged tobe actuated by means of a suitablehydraulic cylinder I25 also carried onthis bracket I23. This indexing plunger I23A has the usual chamfered endI26 which is arranged to engage the various indexing slots I21 formed onthe gear I22 of the indexing blocks I 28 bolted thereon by the screwsI29, there being one of these blocks with an indexing notch I21. foreach of the 4 indexed positions oi. the druni'l.

An additional indexing and steadying device is provided as bestshown inFigurem which oomprises a fluid pressure actuated plunger I3I carried inthe housing 4 and which is actuated by a suitable hydraulic cylinder I32in synchronized relationship with the indexing plunger I23A just Toolfeeding mechanism The driving power for moving the :various breachingand shaving tool feeding devices and the indexing motor III andcylinders I25 and I32 for the indexing plungers is derived from the I053will effect the slow speed operation of the 55 work spindle at the workstation. When in the vertical position shown in Figure VI the respectiverod 09 then stops rotationof the work spindle and the rapid coasting ofthe work spindle and rapid deceleration thereof will be effected by dthe brake drum fluid pressure pump I35 in. the reservoir I00 which isdriven by a suitable electric motor I36 to supply pressure to the feedcylinder I 31; Figure IV, fastened to the base I of the lathe. Attachedtothe reciprocatable piston rod I36 of this cylinder by suitableconnecting means I39 is the rack I40 which is carried in appropriateguide ways MI in the bracket I42 fixed to the side of the uprightsupport 3 of the lathe. This rack I40 engages the large segmental feedgear I43, which is journaled about the trunnion II of the drum I of the4 work spindles asbest shown in'Figures 55 and engages the various vfeedpinions I44, I45 and I46. The gear I44 is fixed on the feed shaft I41which is appropriately journaled in the housing 4 and carries on itpinion I40, Figure V, one

for each of the face broaching slides I 49 and I shown in Figure I.These pinions I46 engage appropriate racks I5I fixed on each of theseslides I49 and I50 so as to eifect the feeding of the tool feedingdevices of Figure X in the line of feeding indicated by-the line XV-XVas described. ,The gear I45 is mounted on. the feed shaft I52, which isjournaled in a housing I53 mounted on the base I between the uprightsupports 2 and 8 and this shaft carries suitable pinions I88 whichengage racks I88 on slides I88A similar to thosemounted on the housing 8to effect feeding movements in the diameter broaching tool feedingdevices along the line XVII- XVII of Figure XI as described. Thegear I88is appropriately mounted on a stud I88 fixed to the base I of the latheand has connected thereto a pinion I81 to rotate with it which drives'an idler gear I88 also iournaled on a stud I88 fixed in the base I ofthe machine. This idler gear I88 in turn drives a gear I88 which iscarried on the feed shaft I8I for the work station Three.

This shaft I8I is Journaled in an appropriate housing I82, also mountedon the base I of the Operation and control The operation of this machineis substantially as follows: Referring particularly to Figure XIX,

assuming a crankshaft to be machined has been properly inserted in awork spindle at the loading station with its ends supported on thecenters I8 of the tailstocks II and suitably gripped intermediate itsends in the chuckingmechanism I8 in the center drive ring gear; theindexing plunger I28a'is fully engaged in an indexing slot I21 and theplunger I8I is engaged in the hole I88 of a center drive chuck. Underthese conditions work may be in the process of being machined at theother three work stations. However, assuming there is no other work inthe machine except that just placed in the work spindle at the loadingstation, solenoid I 88 on the control valve I88 is momentarily energizedcutting off fluid pressure from lines I12, I88, and I88 from enteringline I88 thus rendering the hydraulic motor II1 momentarily inoperativefor releasing strain on the indexing plunger I28a so it may be withdrawnfrom a slot I21 by energizing at the same time the solenoid I18 ofcontrol valve I18 which connects fluid pressure from line I88 and I8I tothe line I82 to actuate the cylinder I28 to withdraw the plunger I28a.Exhaust fluid from this cylinder I28 passes through line I82, throughthe valve I18 into the drain line I88. Also at this'time, the toolslides being fully withdrawn, the dog I88 on the segmental feed gear I88engages the stem of the control valve I88 permitting fluid pressure fromthe lines I12 and I88 to enter line I88 to withdraw the plunger I8I fromthe hole I88 in the center drive head 8, exhaust fluid from thiscylinder passing out throughvline I81, the, valve I88 into the drainline I11.

The withdrawal of the indexing plunger I280. causes its dog I88 to engge and actuate the limit switch 1-8-2 which, through conventionalelectrical apparatus, deenergizes the solenoid I88 and energizessolenoid 288 to actuate the valve I88 to deliver fluid-pressure to theindexing motor II1, exhausted fluid from this indexing motor passing outthrough line I 81, through the normally inoperative deceleration valveI88 into the drain line I88 to cause the drum 1 to index to bring theloaded work spindle to work station One.

As this'indexing motion proceeds the dog 2" on the indexing gear I22actuates the limit switch LS-G, but at this time this limit switch isrendered inoperative by the time limit switch LS 8 which is now beingactuated by the dog -288 on the rack I88 with the tool feeding limitswitch LS--8 just as the notch I 21 comes,-

into proper register with the indexing plunger I28a to at that instantenergize solenoid I8I of control valve I18 causing the index plungerI284 to be thrust into the indexing notch I21.

The spindle now loaded has thus been positioned at work station One andas a result of inserting the indexing plunger I280. into 'the notch I21,its dog I88 actuates the limit switch LS-I which in turn causes thesolenoid I88 of the feed control valve I88 to be energized whereupon thevalve I88 is actuated so as to connect fluid pressure from the fluidpressure pump I88 through the line I 18, the pressure relief valve HI,and line I12, through the valve I88 to the line I18, which is connectedto the bottom of the feed cylinder I81. This effects upward or feedingmovement of the cylinder rod I88 and rack I88 connected to the piston ofthis feed cylinder. The rate of upward movement or feeding rate of thiscylinder rod I 88 is determined by the escape of fluid from the rod endof the cylinder I81 through the line I18, the feed rate control valveI18, which regulates the discharge through the line I18, into the lineI18, and thus to the control valve I88 to the drain line I11, thus backto the fluid reservoir I88. As soon as this cylinder I81 begins itsfeeding operation the dog I88 on the feed segment gear I88 actuates thecontrol valve I88 whereon fluid pressure is delivered through the lineI88 through the valve to the line I81 con- .nected to the indexingplunger cylinder I82 for moving the center drive housing indexingplunger I8I into the socket I88 in the center drive head.8. Exhaustfluid fromthis cylinder I82 passes out through line I88, the controlvalve I88, and into the drain line I11. Also at this time fluid pressureis maintained in the hydraulic motor II1 by the continuous energizing ofsolenoid 288 of valve I88 holding the gear I22 and drum 1 against theindexing plunger I28a in the notch I 21 to prevent any shake or backlash in this mechanism.

The feed cylinder I81 continues its upward feeding movement rotating thesegmental gear I88 and actuating the various feed shafts I81, I52 andI8I to actuate the broaching slides at work stations One andTwo and theshaving tools at work station Three. Also, as pointed out, as

the work spindles in which the work was loaded is indexed to stationOne, the roller 88 on the stud 88, Figure II, efiects operation of theclutch 88 Figure IX causing the spindle to operate at high speed at thiswork station. This forward feeding motion continues and at thecompletion of this motion a dog I99 on the rack I40 engages a limitswitch LS which causes solenoid I of the control valve I19 to beenergized for withdrawing the indexing plunger I23a and at the same timemomentarily energizes the solenoid I83 to release the hydraulic indexingmotor II1 of driving the gear I22 to permit easy withdrawal of theindexing plunger I23a from the indexing notch I21 in the ring gear I22.Also, the solenoid 2000f the valve I95 is energized to effect withdrawalof the plunger I3I from the center drive housing 0 by connecting fluidpressure from the line I92 to the line I90, exhaustfiuid passing outthrough the line I9I into the drain, line I11.

Withdrawal of the index plunger I23a causes its dog I93 to actuate thelimit switch LS-2 which in turn energizes the solenoid 205 of the valveI84, starting up the indexing motor II1 to rotate the gear I22 and drum1 while the tool feeding devices remain at their fully fed in position.

This indexing motion continues for a partial distance of travel of thedrum 1 to the next work station unti] the dog 20I on the gear I22engages the limit switch LS6, the actuation of which energizes thesolenoid I 83 of the valve I84 stopping rotation of the indexing motor II1 and also energizes the solenoid 202 of the control valve IE9whereupon fluid pressure from the line I12 is applied to the line I16freely through the feed rate valve I and the line I14 to the rod end ofthe feed cylinder I31, quickly returning the rack I 40 and the feedingdevices to their withdrawn position, exhaust fluid passing out throughthe line I13 to the control valve I89 into the drain line I11.

As the tool feeding devices and the feed cylinder I31 return to thefully withdrawn position as shown in Figure XIX, a dog 204 on the rackI40 actuates the limit switch which energizes solenoid 205 of the valveI84 to again effect operation of the indexing motor II1, continuing theindexing of the gear I22 and drum 1, and the deceleration of thisindexing motion by the deceleration valve I88 and the ultimate insertionof the indexing plunger I23a in the next indexing notch I21, asdescribed, thus bringing the work spindle to work station Two. This samecycle of operation takes place in bringing this work spindle to workstation Three and back to the loading station where the finished workpiece is removed and an unmachined work piece is again loaded in thisspindle.

The detailed description of the conventional electrical apparatusinterconnecting the limit switches and the solenoids of the controlvalves is not set forth as this apparatus is well known in this art andforms no part of this invention.

The object of this delayed indexing motion is to permit the drum to beindexed away from working position so that the broaching tools may bewithdrawn from the work pieces before the indexing continues to the nextstation so that during this indexing motion the tool will not mar andscratch the work as the work is indexed out of cutting position to thenext station. Thus in this arrangement we have provided a broachinglathe in which the work is indexed from station to station and in whichthe work is indexed partially out of work engaging position at the workstations while the tool feeding devices are in fully fed in position andthen, after the tools have been removed to fully retracted position, theindexing is continued to bring the work to the next station. 7

Having thus fully set forth and described our invention, what we claimas-new and desire to secure by United States Letters Patent-is:

I. In a machine tool having an indexing work carrier, work spindles onsaid carrier, broaching tools located at indexed stages adapted totangentially engage work pieces held in the work spindles, means forindexing said carrier member, means for feeding said broaching tools,

and control means, operable by the movement of said broaching tools whenin fully fed in position, for efiecting a partial indexing of said workcarrier, means associated with the movement of said carrier forconcluding said partial indexing movement of said carrier, and meansoperable by the return movement of said broaching tools to effect thecontinuation of said indexing motion after said broaching tools havereturned to their fully retractedposition.

2. In a machine tool having an indexing work carrier, work spindles onsaid carrier, broaching tools located at indexed stages adapted to befed in planes substantially parallel to the direction of indexingmovement of said work spindles at the work stations, means for indexingsaid carrier member, means for feeding said broaching tools, and controlmeans, operable by the movement of said broaching tools when in fullyfed in position, for eifecting a partial indexing of said work carrier,means associated with the movement of said carrier for concluding saidpartial indexing movement of said carrier, and means operable by thereturn movement of said broaching tools to effect the ontinuation ofsaid indexing motion after said b oaching tools have returned to theirfully retracted position.

WILLIAM F. GROENE. HAROLD J. SIEKM'ANN.

